5 files changed, 31 insertions, 29 deletions

diff --git a/src/core/SkFindAndPlaceGlyph.h b/src/core/SkFindAndPlaceGlyph.h
index 78a02c0e4d..18b93f70a4 100644
--- a/src/core/SkFindAndPlaceGlyph.h
+++ b/src/core/SkFindAndPlaceGlyph.h
@@ -587,9 +587,8 @@ inline void SkFindAndPlaceGlyph::ProcessPosText(
     SkPaint::Align textAlignment,
     SkGlyphCache* cache, ProcessOneGlyph&& processOneGlyph) {
 
-    SkAxisAlignment axisAlignment = SkComputeAxisAlignmentForHText(matrix);
+    SkAxisAlignment axisAlignment = cache->getScalerContext()->computeAxisAlignmentForHText();
     uint32_t mtype = matrix.getType();
-
     LookupGlyph glyphFinder(textEncoding, cache);
 
     // Specialized code for handling the most common case for blink. The while loop is totally
@@ -710,7 +709,8 @@ inline void SkFindAndPlaceGlyph::ProcessText(
     GlyphFindAndPlace<ProcessOneGlyph> findAndPosition{
         [&](typename GlyphFindAndPlace<ProcessOneGlyph>::Variants* to_init) {
             if (cache->isSubpixel()) {
-                SkAxisAlignment axisAlignment = SkComputeAxisAlignmentForHText(matrix);
+                SkAxisAlignment axisAlignment =
+                    cache->getScalerContext()->computeAxisAlignmentForHText();
                 InitSubpixel<ProcessOneGlyph, SkPaint::kLeft_Align>(
                     to_init, axisAlignment, glyphFinder);
             } else {
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index 060e905ec7..017662ff48 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -1318,7 +1318,7 @@ static bool too_big_for_lcd(const SkScalerContext::Rec& rec, bool checkPost2x2)
  *  typically returns the same looking resuts for tiny changes in the matrix.
  */
 static SkScalar sk_relax(SkScalar x) {
-    int n = sk_float_round2int(x * 1024);
+    SkScalar n = SkScalarRoundToScalar(x * 1024);
     return n / 1024.0f;
 }
 
diff --git a/src/core/SkScalerContext.cpp b/src/core/SkScalerContext.cpp
index caef2d1377..c67ca3e9fa 100644
--- a/src/core/SkScalerContext.cpp
+++ b/src/core/SkScalerContext.cpp
@@ -827,13 +827,21 @@ void SkScalerContextRec::computeMatrices(PreMatrixScale preMatrixScale, SkVector
     }
 }
 
-SkAxisAlignment SkComputeAxisAlignmentForHText(const SkMatrix& matrix) {
-    SkASSERT(!matrix.hasPerspective());
-
-    if (0 == matrix[SkMatrix::kMSkewY]) {
+SkAxisAlignment SkScalerContext::computeAxisAlignmentForHText() {
+    // Why fPost2x2 can be used here.
+    // getSingleMatrix multiplies in getLocalMatrix, which consists of
+    // * fTextSize (a scale, which has no effect)
+    // * fPreScaleX (a scale in x, which has no effect)
+    // * fPreSkewX (has no effect, but would on vertical text alignment).
+    // In other words, making the text bigger, stretching it along the
+    // horizontal axis, or fake italicizing it does not move the baseline.
+
+    if (0 == fRec.fPost2x2[1][0]) {
+        // The x axis is mapped onto the x axis.
         return kX_SkAxisAlignment;
     }
-    if (0 == matrix[SkMatrix::kMSkewX]) {
+    if (0 == fRec.fPost2x2[0][0]) {
+        // The x axis is mapped onto the y axis.
         return kY_SkAxisAlignment;
     }
     return kNone_SkAxisAlignment;
diff --git a/src/core/SkScalerContext.h b/src/core/SkScalerContext.h
index 302698ee4e..9249bfb2a9 100644
--- a/src/core/SkScalerContext.h
+++ b/src/core/SkScalerContext.h
@@ -20,6 +20,12 @@ class SkMaskFilter;
 class SkPathEffect;
 class SkRasterizer;
 
+enum SkAxisAlignment {
+    kNone_SkAxisAlignment,
+    kX_SkAxisAlignment,
+    kY_SkAxisAlignment
+};
+
 /*
  *  To allow this to be forward-declared, it must be its own typename, rather
  *  than a nested struct inside SkScalerContext (where it started).
@@ -245,6 +251,13 @@ public:
 
     const Rec& getRec() const { return fRec; }
 
+    /**
+    *  Return the axis (if any) that the baseline for horizontal text should land on.
+    *  As an example, the identity matrix will return kX_SkAxisAlignment
+    */
+    SkAxisAlignment computeAxisAlignmentForHText();
+
+
 protected:
     Rec         fRec;
 
@@ -340,22 +353,6 @@ private:
 
 ///////////////////////////////////////////////////////////////////////////////
 
-enum SkAxisAlignment {
-    kNone_SkAxisAlignment,
-    kX_SkAxisAlignment,
-    kY_SkAxisAlignment
-};
-
-/**
- *  Return the axis (if any) that the baseline for horizontal text will land on
- *  after running through the specified matrix.
- *
- *  As an example, the identity matrix will return kX_SkAxisAlignment
- */
-SkAxisAlignment SkComputeAxisAlignmentForHText(const SkMatrix& matrix);
-
-///////////////////////////////////////////////////////////////////////////////
-
 SkPaint::Hinting SkScalerContextRec::getHinting() const {
     unsigned hint = (fFlags & SkScalerContext::kHinting_Mask) >>
                                             SkScalerContext::kHinting_Shift;
diff --git a/src/ports/SkFontHost_mac.cpp b/src/ports/SkFontHost_mac.cpp
index c4e80b67c0..f1724b675b 100644
--- a/src/ports/SkFontHost_mac.cpp
+++ b/src/ports/SkFontHost_mac.cpp
@@ -1359,13 +1359,10 @@ void SkScalerContext_Mac::generatePath(const SkGlyph& glyph, SkPath* path) {
      *  direction, ask for the path, and then scale the path back down.
      */
     if (fDoSubPosition) {
-        SkMatrix m;
-        fRec.getSingleMatrix(&m);
-
         // start out by assuming that we want no hining in X and Y
         scaleX = scaleY = kScaleForSubPixelPositionHinting;
         // now see if we need to restore hinting for axis-aligned baselines
-        switch (SkComputeAxisAlignmentForHText(m)) {
+        switch (this->computeAxisAlignmentForHText()) {
             case kX_SkAxisAlignment:
                 scaleY = SK_Scalar1; // want hinting in the Y direction
                 break;